Because it uses the car's body steel sheet, taking into account the potential difference was used a steel crimp nut.
It becomes a permanent installation and it rivets, but crimp nut will enable desorption.
For caulking, you need a special tool "Nutter".

For bolting the cowl stay in the main stay of the square pipe, it was used
Really at the time of installation, you do not have to use the neat Nutter
But I think that it was easy you were made of aluminum blind nut was attached as pull in the bolt
It was pretty much we can be mounted without any problems because you have purchased an iron
It survives if it is possible to sell in smaller number Toka two units for too much do not use